To prevent lots of flicker during resizing disable the real-time resizing of the child controls.
To do so override both the Form OnResizeBegin and OnResizeEnd events.

protected override void OnResizeBegin(EventArgs e) 
{
    SuspendLayout();
    base.OnResizeBegin(e);
}

protected override void OnResizeEnd(EventArgs e) 
{
    ResumeLayout();
    base.OnResizeEnd(e);
}